The purpose of the CW4CB project was to contribute to the development of a comprehensive regional strategy for reducing PCB and mercury loads in urban runoff. To meet this goal, a number of priority urban stormwater-related actions required by the Bay TMDLs and the first term MRP (issued in 2009) were implemented as part of the CW4CB project.

CW4CB had four key tasks, the first three of which were field studies in selected watersheds surrounding the Bay, with a focus on old industrial areas with elevated pollutant levels. The studies aimed to evaluate, on a pilot scale, a variety of potential methods to reduce the amount of PCBs and mercury conveyed to the Bay via urban runoff. Since PCBs and mercury are mainly found attached to sediments in the urban environment, these methods focused on containment or removal of polluted sediment. The fourth task was an outreach program to targeted communities.

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Project Facts

  • Recipient: Bay Area Stormwater Management Agencies Association (BASMAA)
  • Funding: USEPA Region IX San Francisco Bay Water Quality Improvement Fund – $5,000,000 (non-federal match= $1,940,000)
  • Project Period: May 3, 2010 – May 2, 2017
  • Partners: California Department of Health Services, Alameda County Flood Control and Water Conservation District, and the cities of Oakland, Richmond, San Carlos, San Jose, and Vallejo.
  • Environmental Results Summary: Clean Watersheds for a Clean Bay Project: Implementing the PCB TMDL

Outputs: Activities, Efforts, and/or Work Product During Project Period

Select five high priority subwatersheds that discharge urban runoff with PCBs and other pollutants to the Bay.Five priority watersheds were selected as described on the Pilot Investigation Watersheds page.
Identify PCB and mercury source areas within the project subwatersheds and refer these sites to regulatory agencies for cleanup and abatement.Sites were identified in all five pilot watersheds as described on the Source Property Identification and Referral page. Seven source properties were referred to regulatory agencies.
Develop methods to enhance removal of sediment with PCBs and other pollutants during municipal sediment management activities.Enhanced operation and maintenance pilot projects including street sweeping, pump station maintenance, storm drain cleaning and street flushing were completed as described on the Enhanced Municipal Operation and Maintenance page.
Retrofit 8 to 10 urban sites with stormwater treatment facilities.Nine urban runoff treatment retrofit projects have been constructed to date (ten were planned but one has not yet been built). Control measures included bioretention facilities, HDS units, a media filter, tree well filters, and a vegetated swale as described on the Urban Runoff Treatment Retrofits page.
Facilitate development and implementation of a regional risk communication and exposure reduction program that focuses on educating the public about the health risks of consuming certain species of Bay fish that contain high levels of PCBs and mercury.CW4CB partnered with the California Department of Public Health, the Aquatic Science Center, the Office of Environmental Health Hazard Assessment, and the Regional Water Board to conduct a regional outreach and education program referred to as the San Francisco Bay Fish Project, as described on the Risk Communication and Exposure Reduction page.
Create public education outreach materials, project web portal, guidance manual, and technical workshops.A project webpage with an interactive map has been created. A Guidance Manual has been developed to assist Permittees in selecting among various types of PCBs and mercury control measures. A technical workshop was held on April 7, 2017 for stormwater program staff, municipal staff, and other individuals.

Outcomes: Environmental Results

Short-Term (1-5 yrs)
Reduce annual loading of PCBs to the Bay by approximately 0.3 – 1.5 kg per year, reducing the current estimated stormwater runoff load of 20 kg/yr by about 2-8%The Source Property Identification and Referral projects reduce PCBs by 142 g/yr. The Enhanced Municipal Operation and Maintenance projects, excluding street sweeping (only baseline sweping conditions were monitored), resulted in a one-time reduction of 78 g of PCBs. The Urban Runoff Treatment Retrofits that were successfully constructed reduce PCBs by 0.18 g/yr.
Treat ~ 2 square miles with stormwater retrofits to reduce potential hydrologic impacts on downstream receiving watersApproximately 0.4 square miles are currently being treated by the constructed stormwater retrofit projects. Once construction of the final project (Ettie St. pump station media filter) has been completed, the total treated area will be approximately 2.2 square miles.
Consumers of Bay fish will have a greater awareness and understanding of fish contamination issues and options for reducing their exposure to pollutantsConsumers of Bay fish have a greater awareness and understanding of fish contamination issues and options for reducing their exposure to pollutants as a result of the San Francisco Bay Fish Project regional outreach and education program.
Long-Term (5-20+yrs)
Identify most promising best management practices (BMPs) for fully meeting the PCB TMDL allocations (2 kg/year) in the future and thereby help address important impairments to the Bay’s beneficial usesValuable data from pilot implementation of Urban Runoff Treatment Retrofits has been obtained. The CW4CB Overall Project Report evaluates the cost effectiveness (cost per mass of PCBs removed by the various control measures evaluated.
Enhance the desirability of commercial enterprise zones and residential neighborhoods in the project watersheds as a result of clean-up activitiesThe source property investigation and referral pilot projects resulted in seven properties being referred for abatement of PCBs and mercury. Additionally, the pilot projects set the foundation for an ongoing effort to identify and abate source properties throughout the Bay Area.